// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/formats/webm/webm_info_parser.h"

#include "base/logging.h"
#include "media/formats/webm/webm_constants.h"

namespace media {

// Default timecode scale if the TimecodeScale element is
// not specified in the INFO element.
static const int kWebMDefaultTimecodeScale = 1000000;

WebMInfoParser::WebMInfoParser()
    : timecode_scale_(-1)
    , duration_(-1)
{
}

WebMInfoParser::~WebMInfoParser() { }

int WebMInfoParser::Parse(const uint8_t* buf, int size)
{
    timecode_scale_ = -1;
    duration_ = -1;

    WebMListParser parser(kWebMIdInfo, this);
    int result = parser.Parse(buf, size);

    if (result <= 0)
        return result;

    // For now we do all or nothing parsing.
    return parser.IsParsingComplete() ? result : 0;
}

WebMParserClient* WebMInfoParser::OnListStart(int id) { return this; }

bool WebMInfoParser::OnListEnd(int id)
{
    if (id == kWebMIdInfo && timecode_scale_ == -1) {
        // Set timecode scale to default value if it isn't present in
        // the Info element.
        timecode_scale_ = kWebMDefaultTimecodeScale;
    }
    return true;
}

bool WebMInfoParser::OnUInt(int id, int64_t val)
{
    if (id != kWebMIdTimecodeScale)
        return true;

    if (timecode_scale_ != -1) {
        DVLOG(1) << "Multiple values for id " << std::hex << id << " specified";
        return false;
    }

    timecode_scale_ = val;
    return true;
}

bool WebMInfoParser::OnFloat(int id, double val)
{
    if (id != kWebMIdDuration) {
        DVLOG(1) << "Unexpected float for id" << std::hex << id;
        return false;
    }

    if (duration_ != -1) {
        DVLOG(1) << "Multiple values for duration.";
        return false;
    }

    duration_ = val;
    return true;
}

bool WebMInfoParser::OnBinary(int id, const uint8_t* data, int size)
{
    if (id == kWebMIdDateUTC) {
        if (size != 8)
            return false;

        int64_t date_in_nanoseconds = 0;
        for (int i = 0; i < size; ++i)
            date_in_nanoseconds = (date_in_nanoseconds << 8) | data[i];

        base::Time::Exploded exploded_epoch;
        exploded_epoch.year = 2001;
        exploded_epoch.month = 1;
        exploded_epoch.day_of_month = 1;
        exploded_epoch.day_of_week = 1;
        exploded_epoch.hour = 0;
        exploded_epoch.minute = 0;
        exploded_epoch.second = 0;
        exploded_epoch.millisecond = 0;
        base::Time out_time;
        if (!base::Time::FromUTCExploded(exploded_epoch, &out_time))
            return false;
        date_utc_ = out_time + base::TimeDelta::FromMicroseconds(date_in_nanoseconds / 1000);
    }
    return true;
}

bool WebMInfoParser::OnString(int id, const std::string& str)
{
    return true;
}

} // namespace media
